power to weight ratio

Power to Weight Ratio for Cyclists: How to calculate, take advantage of, and increase it.

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Power-to-weight ratio (PWR) is a performance metric that is simple to calculate, but also easy to misuse. Individually, tracking PWR over time reflects the combined effect of changes in fitness level (power output) and bodyweight. Between two riders, PWR may predict one cyclist’s potential advantage on specific terrain. And across a population of cyclists, PWR can be used to group riders of similar performance levels. On the other hand, PWR can also lead to excessive focus on both bodyweight and the weight of equipment. Here’s how to calculate, apply, and improve power-to-weight ratio.

What is Power-to-Weight Ratio in Cycling?

To calculate power-to-weight ratio, divide a cyclist’s power output in Watts by the rider’s weight in kilograms. In other words, a cyclist who produces 250 Watts and weighs 70 kilograms would have a PWR of 250 / 70 = 3.57 W/kg.

However, it is important to remember that PWR is not a static number. Rather, it’s a number that corresponds with a specific time or intensity. For instance, a highly trained cyclist might produce 5.5 Watts/kg for 30 minutes. That same rider would have a lower PWR over 60 minutes, like 4.5 W/kg. On the other hand, PWR increases for shorter efforts. Our example rider could perhaps sustain 6.0 W/kg for 15 minutes.

Power-to-weight ratio can also be calculated to correspond to a given intensity level. One of the most common ways indoor cycling apps (Zwift, RGT, etc.) categorize riders for virtual group rides and races is through “power-to-weight ratio at Functional Threshold Power (FTP)”. FTP is the highest average power output a cyclist can maintain for 60 minutes. (Read more about FTP and FTP Tests). On an individual basis, cyclists and coaches use FTP to establish training intensity ranges and evaluate training progress.

What is a good power-to-weight ratio?

Power-to-weight ratio generally increases with fitness and experience. Dr. Andy Coggan aggregated data to describe common power profiles that are conducive to success in certain cycling disciplines. As you might expect, novice cyclists have lower PWR values at FTP (2.0-2.5 W/kg). Experienced age-group competitors are a big higher (3.0-4.0 W/kg). PWRs for high-level age-group competitors are likely to be 4.0-4.75 W/kg). Naturally, elite amateurs and professional cyclists have the highest power-to-weight ratios (5.0-6.0+ W/kg).

Coggan’s power profile table differentiates between male and female PWR ranges. This is often attributed to differences in body composition between males and females. In practice, there is a lot of individual variability and overlap in cyclists with similar training and experience.

Regardless of the number, it’s important to recognize there’s much more to performance than PWR. A “good” or “great” PWR ratio doesn’t mean much without cycling skills, tactical savvy, a solid nutrition strategy, and a winning mindset. PWR is best thought of as another metric you can use to create goals for improvement.

Power-to-weight ratio and power profiling

The fact PWR changes with exercise duration is the basis for power profiling in cycling. Using a variety of testing protocols or data from competition files, coaches create a power profile by recording a rider’s highest average power output for 5 seconds, 1 minute, 5 minutes, 20 minutes, and 60 minutes.

A cyclist’s power profile can help identify strengths, weaknesses, and opportunities for improvement. These power values are converted to PWRs to track the effects of an individual athlete’s training adaptations and weight changes. Power profiles can also be compared across large groups of athletes.

How power-to-weight ratio affects cycling performance

Larger cyclists often produce more power than smaller riders because they have more mass they can use to generate force. On the other hand, lighter riders have less inertia to overcome when trying to get their smaller mass moving.

Power-to-weight ratio affects performance on all types of terrain, but it is easiest to illustrate by comparing uphill cycling performances between two riders. For example: Rider A weighs 76 kg and averaged 275 watts for a 20-minute climb, so his PWR for 20 minutes is 3.6 watts/kg. Rider B weighs 55kg and averaged 210 watts for the same 20-minute climb and has a PWR of 3.8 watts/kg. Despite producing far less power, the 55-kg rider would be further up the climb after 20 minutes. Or put another way, Rider B should be able to drop Rider A.

Is Lighter Always Better?

Not necessarily. PWR is a balance. Cyclists benefit from being light because moving a larger body takes more energy. On the other hand, adequate muscle mass and body fat are necessary for generating more power and staying healthy. From a coaching perspective, we encourage almost all cyclists to prioritize fitness and power production over bodyweight. In our experience with amateur and age group athletes, it is better to be a stronger rider who is 2-5 kilograms heavier than a lighter rider who hasn’t improved power output as much.

Excessive weight loss, and sometimes just excessive focus on bodyweight without actual weight loss, puts athletes at risk. Extremely light athletes struggle to maintain consistent high-quality training sessions. Inadequate energy consumption hinders post-exercise recovery and physiological adaptation to training. And athletes may be more susceptible to illness because they’re not providing their bodies with enough energy to support immune function.

Athletes who restrict caloric intake and/or train excessively are also at increased risk for Relative Energy Deficiency in Sport (RED-s). Furthermore, these behaviors and the beliefs behind them can increase the risk of disordered eating.

Which Is More Important, Losing Weight or Gaining Power?

For novice cyclists and experienced riders who are carrying around more than 10 extra kilograms, losing weight and gaining power are equally important and equally achievable. This also means that heavier cyclists can make bigger improvements in their PWR because they have more room to attack both parts of the equation.

Let’s use a local Colorado Springs climb as an example. Cheyenne Canyon is a 5-kilometer climb with an average 8% grade. Our example rider weighs 75kg with a max sustainable power of 250 watts. Dropping 2.5 kilograms (roughly 5 pounds) with a power output of 250 watts would cut 38 seconds off this rider’s time. Improving power output by 10 watts without any weight loss cuts 41 seconds off his time. This increases to 85 seconds if you improve power output by 20 watts. When you combine losing 2.5 kilograms of bodyweight with a 20-watt increase in sustainable power (both of which are attainable for most cyclists), this rider would go 2:03 faster up Cheyenne Canyon.

Pro cyclists have pretty much maxed out both sides of the PWR equation and they are just about as lean and as powerful as possible. On major climbs, though, that’s why other factors like hydration status, core temperature regulation, and even positioning in the group make such a difference. If a rider can stay cool, stay hydrated, and avoid unnecessary accelerations then he may have more power in reserve to take advantage of his PWR at a crucial time.

When is it better to be a heavier cyclist?

Aerodynamics are more important on flat ground and at higher speeds compared to mountain climbs and slower speeds. A cyclist’s frontal area, a big component of a rider’s aerodynamic drag, doesn’t increase linearly with body size or weight. In other words, a rider who is twice as heavy doesn’t have twice the frontal area in a cycling position.

Larger/heavier riders have an advantage on flat ground and at high speeds because they have the mass to produce more power. Compared with smaller riders, the difference in absolute power output is greater than the difference in aerodynamic drag.

In contrast, time trial bikes and wheels are heavier than bikes used in the mountains because the aerodynamic advantages are greater than the disadvantages from the added weight.

Frequently Asked Questions About Power-to-Weight Ratio

Where Does Power-to-Weight Ratio Make the Biggest Difference?

Power-to-weight ratio makes a difference anytime you accelerate, which is why even large sprinters try to stay lean, too. For the climbers, PWR is most crucial at the steepest parts of big climbs. When the grade is steep, having a higher PWR gives you the ability to accelerate more sharply, which means it provides the opportunity to launch scorching attacks. Riders with lower PWR values can’t accelerate as quickly but may be able to reel you back in when the climb is less severe.

Does Power-to-Weight Ratio Change Throughout the Year?

Yes, and that’s perfectly normal. Elite racers aim to be as strong as possible when they are also as light as they can be. However, that is a delicate balance that can’t be maintained for very long. Gaining weight or losing power means a lot of work to get back to your peak. Therefore, elite athletes try to keep fluctuations in either bodyweight or power output relatively small. Experienced amateur cyclists can expect to see a 15% change from the lowest to highest PWR they see during the year.

Does the Weight of the Bike Get Factored In?

Not typically. At the pro level of cycling the assumption is that the bikes weigh the UCI limit of 6.8 kilograms. In principle, cutting weight on the bike will effectively increase your PWR. However, factoring in bike weight encourages athletes to “buy” their way to their goal PWR. That means they often stop working to optimize power output and bodyweight. For most people, it’s better to maximize PWR regardless of the bike, and then consider weight-savings on the bike as an added race-day advantage.

Does Power-to-Weight Ratio Stay Constant During a Grand Tour Like the Tour de France?

No. Remember, PWR is not a static number. It depends on the duration of the climb, how many hours of racing have been done before that specific climb, how aggressively a particular stage or climb is contested, wind direction, temperature, and even humidity. As riders get tired, overheated/chilled, or dehydrated, PWR goes down. A climb with moderate temperatures, a tailwind, and aggressive racing can result in high PWR values. By the final climbs of long stages and the last mountain stages of the race, even the leaders’ PWRs can drop to around 5 watts/kilogram. In early mountain stages – or for shorter periods within later climbs – they will be around 6 watts/kg.


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Comments 25

  1. Pingback: How Much Does a Bike Weigh? - Cyclingi

  2. Most of us are not pros, so vast numbers race in an age category, where there are significant differences in PWR. People get stuck in comparing their PWR with the average, while they should really be comparing it to their age group.
    Funny how some sites even compare male to female (without any added value) but not age.
    A shame there is no mention of PWR in relation to age. All the benchmarks are absolute, while it is nonsense to compare a 40-60 year old with a 20-30 year old.

  3. Pingback: Cycling for Weight Loss: Pros, Cons, and How to Lose Weight Cycling - CTS

  4. Pingback: Power To Weight - Consummate Athlete

  5. I love reading about the physiology of PWR. And even more so because at 39kg it is extraordinarily difficult to outpower the average person of 70kg +. But I try, and I am happy that my PWR-to-weight ratio is 2.8-2.9 and may 3.0 occasionally.
    Keep up the good work and inspiration.

  6. If you add weight to your bike or body, you have to work harder on a climb to maintain the same speed. Try adding weight over time during training to see if you base power and strength goes up.

    Rockbarcycling.com has a weight that you can attach to bike to make it easy to add weight.

  7. you know all these protein shakes that people take after their cycle ride found out one problem for that it should be taken at the time of beginning to middle to end
    and I dont mean a simple ride to the shops

  8. Hi!

    Excellent stuff.
    Is it feasible for say a rider of 117kg to have natural high power through the pedals or is at not as simple as that?
    Asking for a friend 😉

    1. Andre, I’m looking at this stuff as I had a similar issue. I started training again at 122kgs and very quickly my FTP rose to 300w+ – But thats only a piddly 2.5w/kg. What I did however was work hard to maintain my FTP through extended mid range cardio (C & B group rides on Zwift) and now I’m down to weight (93kg) I have a healthy 3.5w/kg. My sprint power did drop a little, but the reduction in weight means I still snatch green fairly regularly!

  9. Thanks for a great article! I’m female, about 58kg and have been working on increasing my power to weight ratio on a Watt bike. However, my biggest race next year (triathlon) is on the flat, should I be doing something different. Would it actually do me good to gain a few pounds rather than try to lose them? Thanks ever so much for the advice! Stephanie.

    1. power to weight doesn’t matter on the flat, absolute power matters. Adding muscle through strength training will help with the cycling but you would have to be mindful of the running side because runners should be light.

  10. What about those of us who lose weight without trying? As I get older, I’m getting SKINNIER (about 5 kilos less than a few years ago). My power AND speed has dropped on my “uphill time trial.” (Its not for lack of calories . . . I eat 4-5 platefuls at the local buffee! And eating more just makes me move my bowels more.) And yes, my blood tests are normal. Any ideas on how to gain back that extra kilo or to to get me up to “full speed?”

    1. I’m guessing — most would say “wish we had that problem”. If you’re not doing major workouts (or working out at all), and also are eating a good 2500+ calories, then you shouldn’t be losing weight. If so — you might want to get a medical checkup.
      Of course — if your doing the equivalent of the Tour de France (6000+ calories per day) — well of course you have to eat more — WAY more!

  11. So, here’s the extra question part. The weight part is pretty obvious. How about the power part.
    — How does one go about gaining it?
    — Go about keeping it (sustaining over weeks, months, years)?
    — And isn’t there also just a genetic component going on here — some people
    are never going to get to their desired power level?

  12. Great article as usual, Chris.
    Obviously, more power is good, and less weight is good (up to a point).
    What I have always wondered is…how gradient fits into the PWR equation. For example…
    As the gradients get really steep (e.g. above a 10% gradient), a 5% loss in weight will likely become more important than a 5% increase in power in terms of increasing your climbing speed. This is where the really small riders can excel on climbs (e.g. Nairo Quintana & Joaquim Rodriguez).
    Conversely, for shallower gradients (e.g. less than 5%), a 5% increase in power will likely see your speed increase more than through a 5% drop in weight. This is where the tall but slim power-houses can excel on climbs (e.g. Tom Dumoulin & Brad Wiggins a few years ago).
    Therefore, do you know of any any research which helps to quantify how the gradient of a climb factors into the PWR equation, and where the tipping point is in terms of gradient when power and weight are of equal importance?
    Best regards,
    Gary

  13. Pingback: Correcting the Biggest Mistake Cyclists and Triathletes Make on Climbs - CTS

  14. Good explanations and examples.
    Whatever your current PWR you’ve got three performance barriers to over come
    Hydration, Fueling and Cooling.
    Fall behind on any of these and power and endurance falls quickly.

  15. Hi Chris,
    Enjoyed the PWR article but it destroys my theory of why I am able to out climb other serious bikers. I am a weekend rider at best and carry 50-75 pounds over others. During the flat portions of the rides I have to push it to keep pace but once the climbing begins I find myself at the front. I find it very difficult to go as slow as most are comfortable with during climbing workouts. I assumed my climbing was because I was able to put so much more weight on the pedals.
    Thx,
    Jeff

    1. Just some initial thoughts Jeff…
      Possibly poorer aerodynamics than your friends on the flat (e.g. higher riding position, or looser-fitting clothing).
      Also, if the climbs are not too steep, your extra weight won’t penalise you too much.
      Additionally, some people can put out a lot more power in a climbing position than they can in a flat-terrain position (either naturally, or due to spending a lot more time cycling in a climbing position).
      Best,
      Gary

    2. It also depends on what sort of climb you are doing. As per the original article power/weight also has a time dimension. On short sharp climbs that only take a minute or two at most power is really the most important. These are the sort of climbs you see in the early season “classics” and these are often best handled by relatively chunky riders not out and out climbers.

      For this sort of climb your theory about weight is not altogether wrong. If you tackle them by standing and shifting your body from side to side you extra pounds will produce more power. But only for a relatively short time, this sort of approach is inefficient and you will quickly tire.

      Weight>Power really comes into its own on longer climbs that take many minutes or hours. It would be extremely surprising if you can drop your mates on these sorts of climbs while giving them 50-75lbs.

      If you do then the reason will most likely not be physiological but mental, there is no hiding place on climbs and often the difference between winners and losers is not just w/kg but also how you deal with the unrelenting pain.

  16. Pingback: Good Article on Power-to-Weight Ratio…. | PROJECT 10%

  17. I’m curious if the same principles apply to a time trial? Specifically does PWR have the same affect on a flat 20 or 40k TT?

  18. Hi Chris,
    My wife and I have been riding racing for over 20 years. We spent a couple winters working out in your Tucson facility, we live in Tucson. She is 5′-1″ 120 lbs and I’m 6′-3″ 185 lbs. strangely enough we have almost identical PWR to weight numbers, about 3.25 watts/Kg, yet I consistantly out climb her when doing long climbs like Mt Lemmon. Shouldn’t she be able to leave me behind on the long climbs or is it possibly more about duration that each of us can hold a specific power? Thanks. Enjoying your TDF articles and looking forward to this winter and more sessions at your wonderful facility just 3 miles from our home.
    Cheers,
    Jeff & Carolyn

    1. If you have the same W/kg as your partner uphill you’ll be similar speeds… but you weigh more, so your absolute power is higher, on the flat they are going harder than you relative to their absolute power being lower. When you hit the climb you will be fresher. Also males are not comparable to females and visa versa completely different physiology. Then there’s the fact a watt is not just a watt. Depending on muscle fibre makeup some people can put more power down on the flats or the climbs.

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